Toothaches are commonly caused by infections of the gums. Often times these common bacterial infections of the gum are easily treated with available antibiotics like metronidazole and amoxicillin. However, the frequency and dosing of taking these antibiotics may vary depending on the type of infection as well as the gravity of the infection. Tooth abscess is a common reason for toothaches, and they can range from mild to severe. Aside from the nasty pain within, the infection can also contribute to bad mouth odor which adds to the annoying situation. To treat the bacterial infection, you will need a good antibiotic drug that will kill the bacteria and restore the normal health of your gums.